Strategic Lateral Offset Procedures (SLOP) are mitigating the risk of vertical collision and wake turbulence encounters between aircraft with high precision navigation capabilities. Provisions of SLOP are published in ICAO Doc 4444 (PANS-ATM) as special procedures for oceanic and remote continental airspace. Strategic Lateral Offset Procedures are pilot initiated and more or less transparent to controllers. After the mid-air collision in Brazil (GOL Transportes Aéreos, September 2006), some stakeholders in air transport industry highlighted the issue that SLOP have not been implemented by Air Traffic Services (ATS) authorities as widely as possible. ICAO has since started to investigate and develop SLOP to extend its applicability to other than oceanic and remote airspaces.